| 不同规格鱼鳞坑坡面侵蚀过程及特征研究 |
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| 引用本文： | 侯雷,谢欣利,姚冲,吴发启.不同规格鱼鳞坑坡面侵蚀过程及特征研究[J].农业工程学报,2020,36(8):62-68. |
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| 作者姓名： | 侯雷 谢欣利 姚冲 吴发启 |
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| 作者单位： | 西北农林科技大学水土保持研究所,杨凌 712100;西北农林科技大学资源环境学院,杨凌 712100 |
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| 基金项目： | 国家自然科学基金"黄土坡耕地作物覆盖与管理的防蚀作用研究"（41977065） |
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| 摘 要： | 探究不同雨强下鱼鳞坑措施的坡面侵蚀规律及特征,对进一步明晰该措施的径流泥沙调控机制具有重要意义。该研究采用小区模拟降雨试验,研究3种雨强(40,70和100 mm/h)条件下2种规格鱼鳞坑坡面的蓄水保土效益及侵蚀过程,并探讨鱼鳞坑坡面水沙特征及其与细沟形态之间的关系。结果表明,鱼鳞坑的径流泥沙调控作用明显但也存在阈值,在措施被冲垮前,各处理减流效益和减沙效益分别为66.02%~82.20%和85.77%~91.91%;平均径流强度和输沙速率分别为平整坡面的18.87%~33.21%和10.04%~15.38%;当鱼鳞坑被冲垮后,坡面产流量和产沙量分别为平整坡面的1.00~1.22倍和1.39~3.53倍,其平均径流强度和输沙速率分别为鱼鳞坑冲垮前的4.60~7.46倍和13.70~16.75倍。鱼鳞坑坡面径流含沙率在措施冲垮前后的差异较大,水沙关系线性拟合的斜率在措施被冲垮前为0.020和0.035,而冲垮后斜率为0.205和0.231,同时坡面总产沙量和峰值产流产沙量与细沟形态显著相关。因此,鱼鳞坑措施对坡面产流产沙特征及形态的影响在其调控阈值前后有较大差异。研究可为鱼鳞坑坡面水土流失的研究可为区域水土保持措施配置及管理提供相应的依据。
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| 关 键 词： | 侵蚀 径流 泥沙 鱼鳞坑 水沙关系 调控作用 细沟 |
| 收稿时间： | 2020/1/17 0:00:00 |
| 修稿时间： | 2020/4/1 0:00:00 |
Erosion process and characteristics of different specifications of fish-scale pit slope |
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| Hou Lei,Xie Xinli,Yao Chong,Wu Faqi.Erosion process and characteristics of different specifications of fish-scale pit slope[J].Transactions of the Chinese Society of Agricultural Engineering,2020,36(8):62-68. |
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| Authors: | Hou Lei Xie Xinli Yao Chong Wu Faqi |
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| Institution: | 1. Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China;,1. Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China;,1. Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China; and 2. College of Resources and Environment Sciences, Northwest A&F University, Yangling 712100, China; |
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| Abstract: | This study explored the characteristics of fish-scale pit slope erosion under different rainfall intensities. Two specifications of fish-scale pits (0.6 m×0.4 m×0.1 m and 0.4 m×0.3 m×0.1 m) were adopted in the simulated rainfall experiment including three rainfall intensities (40, 70 and 100 mm/h). Runoff and sediment samples were collected to calculate the benefits of runoff and sediment reduction, and the widths and depths of rills were measured to describe the rill morphology. Runoff generation time and fish-scale pit damage time were also observed and recorded during the rainfall process. Moreover, runoff rate and sediment transport rate were calculated and the relationships between runoff and sediment yield and rill morphology were analyzed. The results showed that when the rainfall lasted for one hour, the morphology of fish-scale pits were intact under the 40 mm/h rainfall intensity, but the fish-scale pits were damaged under the 70 and 100 mm/h rainfall intensities. The fish-scale pit had an obvious effect on runoff and sediment yields and the threshold existed. Based on the fish-scale pit damage time, the fish-scale pit slope erosion was divided into two processes. The runoff generation time increased with decrease of the rainfall intensity. The two specifications of fish-scale pits delayed the runoff generation time, which was 27.79%-59.12% and 72.42%-116.85% higher than smooth slope. The small fish-scale pits were easier to be damaged than the big fish-scale pits under the same rainfall intensity. The benefits of runoff and sediment reduction were 66.02%-82.20% and 85.77%-91.91%, and the mean value of runoff rate and sediment transport rate were 18.87%-33.21% and 10.04%-15.38% of the smooth slope before the fish-scale pits damage. After fish-scale pits damage, slope measures would lose the regulatory function and would have the negative effects on soil and water reduction. The runoff rate and sediment transport rate were suddenly increased and the mean value of runoff rate and sediment transport rate were 4.60-7.46 and 13.70-16.75 times that before fish-scale pits damage. The mean runoff rate and sediment transport rate of the smooth slope were 51.50 mm/h and 3.04 kg/(m2·h) under the 70 mm/h rainfall intensity, and the mean runoff rate and sediment transport rate were 78.61 mm/h and 5.20 kg/(m2·h) under the 100 mm/h rainfall intensity. The flow-sediment relationship under 100 mm/h rainfall intensity showed that the sediment was greatly different before and after fish-scale pits damage. The sediment yield could be decreased by fish-scale pit measures application. The slopes of linear regression equations for fitting the relationship between runoff and sediment were 0.020-0.035 before fish-scale pit damage and they were increased to 0.205-0.231 after fish-scale pit damage. The slopes of linear regression equations for fitting the relationship between runoff and sediment on smooth slope was 0.038 under 100 mm/h rainfall intensity. The width of rill had significant correlation with peak sediment yield (P<0.01) and the depth of rill had significant relationship with total sediment yield and peak runoff yield (P<0.01). The overflow time of fish-scale pit was an important indicator of the regulation threshold of runoff and sediment, and slope erosion characteristic and rill morphology showed obvious difference before and after fish-scale pits damage. This study will provide valuable information for allocation and management of regional soil and water conservation measures. |
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| Keywords: | erosion runoff sediments fish-scale pit flow-sediment relationship regulation function rills |
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